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regexp-macro-assembler-mips.cc
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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/v8.h"
#if V8_TARGET_ARCH_MIPS
#include "src/code-stubs.h"
#include "src/log.h"
#include "src/macro-assembler.h"
#include "src/regexp-macro-assembler.h"
#include "src/regexp-stack.h"
#include "src/unicode.h"
#include "src/mips/regexp-macro-assembler-mips.h"
namespace v8 {
namespace internal {
#ifndef V8_INTERPRETED_REGEXP
/*
* This assembler uses the following register assignment convention
* - t7 : Temporarily stores the index of capture start after a matching pass
* for a global regexp.
* - t1 : Pointer to current code object (Code*) including heap object tag.
* - t2 : Current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character offset!
* - t3 : Currently loaded character. Must be loaded using
* LoadCurrentCharacter before using any of the dispatch methods.
* - t4 : Points to tip of backtrack stack
* - t5 : Unused.
* - t6 : End of input (points to byte after last character in input).
* - fp : Frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - sp : Points to tip of C stack.
*
* The remaining registers are free for computations.
* Each call to a public method should retain this convention.
*
* The stack will have the following structure:
*
* - fp[64] Isolate* isolate (address of the current isolate)
* - fp[60] direct_call (if 1, direct call from JavaScript code,
* if 0, call through the runtime system).
* - fp[56] stack_area_base (High end of the memory area to use as
* backtracking stack).
* - fp[52] capture array size (may fit multiple sets of matches)
* - fp[48] int* capture_array (int[num_saved_registers_], for output).
* - fp[44] secondary link/return address used by native call.
* --- sp when called ---
* - fp[40] return address (lr).
* - fp[36] old frame pointer (r11).
* - fp[0..32] backup of registers s0..s7.
* --- frame pointer ----
* - fp[-4] end of input (address of end of string).
* - fp[-8] start of input (address of first character in string).
* - fp[-12] start index (character index of start).
* - fp[-16] void* input_string (location of a handle containing the string).
* - fp[-20] success counter (only for global regexps to count matches).
* - fp[-24] Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a
* non-position.
* - fp[-28] At start (if 1, we are starting at the start of the
* string, otherwise 0)
* - fp[-32] register 0 (Only positions must be stored in the first
* - register 1 num_saved_registers_ registers)
* - ...
* - register num_registers-1
* --- sp ---
*
* The first num_saved_registers_ registers are initialized to point to
* "character -1" in the string (i.e., char_size() bytes before the first
* character of the string). The remaining registers start out as garbage.
*
* The data up to the return address must be placed there by the calling
* code and the remaining arguments are passed in registers, e.g. by calling the
* code entry as cast to a function with the signature:
* int (*match)(String* input_string,
* int start_index,
* Address start,
* Address end,
* Address secondary_return_address, // Only used by native call.
* int* capture_output_array,
* byte* stack_area_base,
* bool direct_call = false)
* The call is performed by NativeRegExpMacroAssembler::Execute()
* (in regexp-macro-assembler.cc) via the CALL_GENERATED_REGEXP_CODE macro
* in mips/simulator-mips.h.
* When calling as a non-direct call (i.e., from C++ code), the return address
* area is overwritten with the ra register by the RegExp code. When doing a
* direct call from generated code, the return address is placed there by
* the calling code, as in a normal exit frame.
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(
Mode mode,
int registers_to_save,
Zone* zone)
: NativeRegExpMacroAssembler(zone),
masm_(new MacroAssembler(zone->isolate(), NULL, kRegExpCodeSize)),
mode_(mode),
num_registers_(registers_to_save),
num_saved_registers_(registers_to_save),
entry_label_(),
start_label_(),
success_label_(),
backtrack_label_(),
exit_label_(),
internal_failure_label_() {
ASSERT_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code later.
// If the code gets too big or corrupted, an internal exception will be
// raised, and we will exit right away.
__ bind(&internal_failure_label_);
__ li(v0, Operand(FAILURE));
__ Ret();
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerMIPS::~RegExpMacroAssemblerMIPS() {
delete masm_;
// Unuse labels in case we throw away the assembler without calling GetCode.
entry_label_.Unuse();
start_label_.Unuse();
success_label_.Unuse();
backtrack_label_.Unuse();
exit_label_.Unuse();
check_preempt_label_.Unuse();
stack_overflow_label_.Unuse();
internal_failure_label_.Unuse();
}
int RegExpMacroAssemblerMIPS::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerMIPS::AdvanceCurrentPosition(int by) {
if (by != 0) {
__ Addu(current_input_offset(),
current_input_offset(), Operand(by * char_size()));
}
}
void RegExpMacroAssemblerMIPS::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(reg < num_registers_);
if (by != 0) {
__ lw(a0, register_location(reg));
__ Addu(a0, a0, Operand(by));
__ sw(a0, register_location(reg));
}
}
void RegExpMacroAssemblerMIPS::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(a0);
__ Addu(a0, a0, code_pointer());
__ Jump(a0);
}
void RegExpMacroAssemblerMIPS::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerMIPS::CheckCharacter(uint32_t c, Label* on_equal) {
BranchOrBacktrack(on_equal, eq, current_character(), Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckCharacterGT(uc16 limit, Label* on_greater) {
BranchOrBacktrack(on_greater, gt, current_character(), Operand(limit));
}
void RegExpMacroAssemblerMIPS::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ lw(a0, MemOperand(frame_pointer(), kStartIndex));
BranchOrBacktrack(¬_at_start, ne, a0, Operand(zero_reg));
// If we did, are we still at the start of the input?
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ Addu(a0, end_of_input_address(), Operand(current_input_offset()));
BranchOrBacktrack(on_at_start, eq, a0, Operand(a1));
__ bind(¬_at_start);
}
void RegExpMacroAssemblerMIPS::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ lw(a0, MemOperand(frame_pointer(), kStartIndex));
BranchOrBacktrack(on_not_at_start, ne, a0, Operand(zero_reg));
// If we did, are we still at the start of the input?
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ Addu(a0, end_of_input_address(), Operand(current_input_offset()));
BranchOrBacktrack(on_not_at_start, ne, a0, Operand(a1));
}
void RegExpMacroAssemblerMIPS::CheckCharacterLT(uc16 limit, Label* on_less) {
BranchOrBacktrack(on_less, lt, current_character(), Operand(limit));
}
void RegExpMacroAssemblerMIPS::CheckGreedyLoop(Label* on_equal) {
Label backtrack_non_equal;
__ lw(a0, MemOperand(backtrack_stackpointer(), 0));
__ Branch(&backtrack_non_equal, ne, current_input_offset(), Operand(a0));
__ Addu(backtrack_stackpointer(),
backtrack_stackpointer(),
Operand(kPointerSize));
__ bind(&backtrack_non_equal);
BranchOrBacktrack(on_equal, eq, current_input_offset(), Operand(a0));
}
void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ lw(a0, register_location(start_reg)); // Index of start of capture.
__ lw(a1, register_location(start_reg + 1)); // Index of end of capture.
__ Subu(a1, a1, a0); // Length of capture.
// If length is zero, either the capture is empty or it is not participating.
// In either case succeed immediately.
__ Branch(&fallthrough, eq, a1, Operand(zero_reg));
__ Addu(t5, a1, current_input_offset());
// Check that there are enough characters left in the input.
BranchOrBacktrack(on_no_match, gt, t5, Operand(zero_reg));
if (mode_ == ASCII) {
Label success;
Label fail;
Label loop_check;
// a0 - offset of start of capture.
// a1 - length of capture.
__ Addu(a0, a0, Operand(end_of_input_address()));
__ Addu(a2, end_of_input_address(), Operand(current_input_offset()));
__ Addu(a1, a0, Operand(a1));
// a0 - Address of start of capture.
// a1 - Address of end of capture.
// a2 - Address of current input position.
Label loop;
__ bind(&loop);
__ lbu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lbu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
__ Branch(&loop_check, eq, t0, Operand(a3));
// Mismatch, try case-insensitive match (converting letters to lower-case).
__ Or(a3, a3, Operand(0x20)); // Convert capture character to lower-case.
__ Or(t0, t0, Operand(0x20)); // Also convert input character.
__ Branch(&fail, ne, t0, Operand(a3));
__ Subu(a3, a3, Operand('a'));
__ Branch(&loop_check, ls, a3, Operand('z' - 'a'));
// Latin-1: Check for values in range [224,254] but not 247.
__ Subu(a3, a3, Operand(224 - 'a'));
// Weren't Latin-1 letters.
__ Branch(&fail, hi, a3, Operand(254 - 224));
// Check for 247.
__ Branch(&fail, eq, a3, Operand(247 - 224));
__ bind(&loop_check);
__ Branch(&loop, lt, a0, Operand(a1));
__ jmp(&success);
__ bind(&fail);
GoTo(on_no_match);
__ bind(&success);
// Compute new value of character position after the matched part.
__ Subu(current_input_offset(), a2, end_of_input_address());
} else {
ASSERT(mode_ == UC16);
// Put regexp engine registers on stack.
RegList regexp_registers_to_retain = current_input_offset().bit() |
current_character().bit() | backtrack_stackpointer().bit();
__ MultiPush(regexp_registers_to_retain);
int argument_count = 4;
__ PrepareCallCFunction(argument_count, a2);
// a0 - offset of start of capture.
// a1 - length of capture.
// Put arguments into arguments registers.
// Parameters are
// a0: Address byte_offset1 - Address captured substring's start.
// a1: Address byte_offset2 - Address of current character position.
// a2: size_t byte_length - length of capture in bytes(!).
// a3: Isolate* isolate.
// Address of start of capture.
__ Addu(a0, a0, Operand(end_of_input_address()));
// Length of capture.
__ mov(a2, a1);
// Save length in callee-save register for use on return.
__ mov(s3, a1);
// Address of current input position.
__ Addu(a1, current_input_offset(), Operand(end_of_input_address()));
// Isolate.
__ li(a3, Operand(ExternalReference::isolate_address(masm_->isolate())));
{
AllowExternalCallThatCantCauseGC scope(masm_);
ExternalReference function =
ExternalReference::re_case_insensitive_compare_uc16(masm_->isolate());
__ CallCFunction(function, argument_count);
}
// Restore regexp engine registers.
__ MultiPop(regexp_registers_to_retain);
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
// Check if function returned non-zero for success or zero for failure.
BranchOrBacktrack(on_no_match, eq, v0, Operand(zero_reg));
// On success, increment position by length of capture.
__ Addu(current_input_offset(), current_input_offset(), Operand(s3));
}
__ bind(&fallthrough);
}
void RegExpMacroAssemblerMIPS::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Label success;
// Find length of back-referenced capture.
__ lw(a0, register_location(start_reg));
__ lw(a1, register_location(start_reg + 1));
__ Subu(a1, a1, a0); // Length to check.
// Succeed on empty capture (including no capture).
__ Branch(&fallthrough, eq, a1, Operand(zero_reg));
__ Addu(t5, a1, current_input_offset());
// Check that there are enough characters left in the input.
BranchOrBacktrack(on_no_match, gt, t5, Operand(zero_reg));
// Compute pointers to match string and capture string.
__ Addu(a0, a0, Operand(end_of_input_address()));
__ Addu(a2, end_of_input_address(), Operand(current_input_offset()));
__ Addu(a1, a1, Operand(a0));
Label loop;
__ bind(&loop);
if (mode_ == ASCII) {
__ lbu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lbu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
} else {
ASSERT(mode_ == UC16);
__ lhu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lhu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
}
BranchOrBacktrack(on_no_match, ne, a3, Operand(t0));
__ Branch(&loop, lt, a0, Operand(a1));
// Move current character position to position after match.
__ Subu(current_input_offset(), a2, end_of_input_address());
__ bind(&fallthrough);
}
void RegExpMacroAssemblerMIPS::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
BranchOrBacktrack(on_not_equal, ne, current_character(), Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
__ And(a0, current_character(), Operand(mask));
Operand rhs = (c == 0) ? Operand(zero_reg) : Operand(c);
BranchOrBacktrack(on_equal, eq, a0, rhs);
}
void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
__ And(a0, current_character(), Operand(mask));
Operand rhs = (c == 0) ? Operand(zero_reg) : Operand(c);
BranchOrBacktrack(on_not_equal, ne, a0, rhs);
}
void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
ASSERT(minus < String::kMaxUtf16CodeUnit);
__ Subu(a0, current_character(), Operand(minus));
__ And(a0, a0, Operand(mask));
BranchOrBacktrack(on_not_equal, ne, a0, Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckCharacterInRange(
uc16 from,
uc16 to,
Label* on_in_range) {
__ Subu(a0, current_character(), Operand(from));
// Unsigned lower-or-same condition.
BranchOrBacktrack(on_in_range, ls, a0, Operand(to - from));
}
void RegExpMacroAssemblerMIPS::CheckCharacterNotInRange(
uc16 from,
uc16 to,
Label* on_not_in_range) {
__ Subu(a0, current_character(), Operand(from));
// Unsigned higher condition.
BranchOrBacktrack(on_not_in_range, hi, a0, Operand(to - from));
}
void RegExpMacroAssemblerMIPS::CheckBitInTable(
Handle<ByteArray> table,
Label* on_bit_set) {
__ li(a0, Operand(table));
if (mode_ != ASCII || kTableMask != String::kMaxOneByteCharCode) {
__ And(a1, current_character(), Operand(kTableSize - 1));
__ Addu(a0, a0, a1);
} else {
__ Addu(a0, a0, current_character());
}
__ lbu(a0, FieldMemOperand(a0, ByteArray::kHeaderSize));
BranchOrBacktrack(on_bit_set, ne, a0, Operand(zero_reg));
}
bool RegExpMacroAssemblerMIPS::CheckSpecialCharacterClass(uc16 type,
Label* on_no_match) {
// Range checks (c in min..max) are generally implemented by an unsigned
// (c - min) <= (max - min) check.
switch (type) {
case 's':
// Match space-characters.
if (mode_ == ASCII) {
// One byte space characters are '\t'..'\r', ' ' and \u00a0.
Label success;
__ Branch(&success, eq, current_character(), Operand(' '));
// Check range 0x09..0x0d.
__ Subu(a0, current_character(), Operand('\t'));
__ Branch(&success, ls, a0, Operand('\r' - '\t'));
// \u00a0 (NBSP).
BranchOrBacktrack(on_no_match, ne, a0, Operand(0x00a0 - '\t'));
__ bind(&success);
return true;
}
return false;
case 'S':
// The emitted code for generic character classes is good enough.
return false;
case 'd':
// Match ASCII digits ('0'..'9').
__ Subu(a0, current_character(), Operand('0'));
BranchOrBacktrack(on_no_match, hi, a0, Operand('9' - '0'));
return true;
case 'D':
// Match non ASCII-digits.
__ Subu(a0, current_character(), Operand('0'));
BranchOrBacktrack(on_no_match, ls, a0, Operand('9' - '0'));
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029).
__ Xor(a0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c.
__ Subu(a0, a0, Operand(0x0b));
BranchOrBacktrack(on_no_match, ls, a0, Operand(0x0c - 0x0b));
if (mode_ == UC16) {
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
__ Subu(a0, a0, Operand(0x2028 - 0x0b));
BranchOrBacktrack(on_no_match, ls, a0, Operand(1));
}
return true;
}
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029).
__ Xor(a0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c.
__ Subu(a0, a0, Operand(0x0b));
if (mode_ == ASCII) {
BranchOrBacktrack(on_no_match, hi, a0, Operand(0x0c - 0x0b));
} else {
Label done;
BranchOrBacktrack(&done, ls, a0, Operand(0x0c - 0x0b));
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
__ Subu(a0, a0, Operand(0x2028 - 0x0b));
BranchOrBacktrack(on_no_match, hi, a0, Operand(1));
__ bind(&done);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
BranchOrBacktrack(on_no_match, hi, current_character(), Operand('z'));
}
ExternalReference map = ExternalReference::re_word_character_map();
__ li(a0, Operand(map));
__ Addu(a0, a0, current_character());
__ lbu(a0, MemOperand(a0, 0));
BranchOrBacktrack(on_no_match, eq, a0, Operand(zero_reg));
return true;
}
case 'W': {
Label done;
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ Branch(&done, hi, current_character(), Operand('z'));
}
ExternalReference map = ExternalReference::re_word_character_map();
__ li(a0, Operand(map));
__ Addu(a0, a0, current_character());
__ lbu(a0, MemOperand(a0, 0));
BranchOrBacktrack(on_no_match, ne, a0, Operand(zero_reg));
if (mode_ != ASCII) {
__ bind(&done);
}
return true;
}
case '*':
// Match any character.
return true;
// No custom implementation (yet): s(UC16), S(UC16).
default:
return false;
}
}
void RegExpMacroAssemblerMIPS::Fail() {
__ li(v0, Operand(FAILURE));
__ jmp(&exit_label_);
}
Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
Label return_v0;
if (masm_->has_exception()) {
// If the code gets corrupted due to long regular expressions and lack of
// space on trampolines, an internal exception flag is set. If this case
// is detected, we will jump into exit sequence right away.
__ bind_to(&entry_label_, internal_failure_label_.pos());
} else {
// Finalize code - write the entry point code now we know how many
// registers we need.
// Entry code:
__ bind(&entry_label_);
// Tell the system that we have a stack frame. Because the type is MANUAL,
// no is generated.
FrameScope scope(masm_, StackFrame::MANUAL);
// Actually emit code to start a new stack frame.
// Push arguments
// Save callee-save registers.
// Start new stack frame.
// Store link register in existing stack-cell.
// Order here should correspond to order of offset constants in header file.
RegList registers_to_retain = s0.bit() | s1.bit() | s2.bit() |
s3.bit() | s4.bit() | s5.bit() | s6.bit() | s7.bit() | fp.bit();
RegList argument_registers = a0.bit() | a1.bit() | a2.bit() | a3.bit();
__ MultiPush(argument_registers | registers_to_retain | ra.bit());
// Set frame pointer in space for it if this is not a direct call
// from generated code.
__ Addu(frame_pointer(), sp, Operand(4 * kPointerSize));
__ mov(a0, zero_reg);
__ push(a0); // Make room for success counter and initialize it to 0.
__ push(a0); // Make room for "position - 1" constant (value irrelevant).
// Check if we have space on the stack for registers.
Label stack_limit_hit;
Label stack_ok;
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(masm_->isolate());
__ li(a0, Operand(stack_limit));
__ lw(a0, MemOperand(a0));
__ Subu(a0, sp, a0);
// Handle it if the stack pointer is already below the stack limit.
__ Branch(&stack_limit_hit, le, a0, Operand(zero_reg));
// Check if there is room for the variable number of registers above
// the stack limit.
__ Branch(&stack_ok, hs, a0, Operand(num_registers_ * kPointerSize));
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ li(v0, Operand(EXCEPTION));
__ jmp(&return_v0);
__ bind(&stack_limit_hit);
CallCheckStackGuardState(a0);
// If returned value is non-zero, we exit with the returned value as result.
__ Branch(&return_v0, ne, v0, Operand(zero_reg));
__ bind(&stack_ok);
// Allocate space on stack for registers.
__ Subu(sp, sp, Operand(num_registers_ * kPointerSize));
// Load string end.
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
// Load input start.
__ lw(a0, MemOperand(frame_pointer(), kInputStart));
// Find negative length (offset of start relative to end).
__ Subu(current_input_offset(), a0, end_of_input_address());
// Set a0 to address of char before start of the input string
// (effectively string position -1).
__ lw(a1, MemOperand(frame_pointer(), kStartIndex));
__ Subu(a0, current_input_offset(), Operand(char_size()));
__ sll(t5, a1, (mode_ == UC16) ? 1 : 0);
__ Subu(a0, a0, t5);
// Store this value in a local variable, for use when clearing
// position registers.
__ sw(a0, MemOperand(frame_pointer(), kInputStartMinusOne));
// Initialize code pointer register
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
Label load_char_start_regexp, start_regexp;
// Load newline if index is at start, previous character otherwise.
__ Branch(&load_char_start_regexp, ne, a1, Operand(zero_reg));
__ li(current_character(), Operand('\n'));
__ jmp(&start_regexp);
// Global regexp restarts matching here.
__ bind(&load_char_start_regexp);
// Load previous char as initial value of current character register.
LoadCurrentCharacterUnchecked(-1, 1);
__ bind(&start_regexp);
// Initialize on-stack registers.
if (num_saved_registers_ > 0) { // Always is, if generated from a regexp.
// Fill saved registers with initial value = start offset - 1.
if (num_saved_registers_ > 8) {
// Address of register 0.
__ Addu(a1, frame_pointer(), Operand(kRegisterZero));
__ li(a2, Operand(num_saved_registers_));
Label init_loop;
__ bind(&init_loop);
__ sw(a0, MemOperand(a1));
__ Addu(a1, a1, Operand(-kPointerSize));
__ Subu(a2, a2, Operand(1));
__ Branch(&init_loop, ne, a2, Operand(zero_reg));
} else {
for (int i = 0; i < num_saved_registers_; i++) {
__ sw(a0, register_location(i));
}
}
}
// Initialize backtrack stack pointer.
__ lw(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
__ jmp(&start_label_);
// Exit code:
if (success_label_.is_linked()) {
// Save captures when successful.
__ bind(&success_label_);
if (num_saved_registers_ > 0) {
// Copy captures to output.
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ lw(a0, MemOperand(frame_pointer(), kRegisterOutput));
__ lw(a2, MemOperand(frame_pointer(), kStartIndex));
__ Subu(a1, end_of_input_address(), a1);
// a1 is length of input in bytes.
if (mode_ == UC16) {
__ srl(a1, a1, 1);
}
// a1 is length of input in characters.
__ Addu(a1, a1, Operand(a2));
// a1 is length of string in characters.
ASSERT_EQ(0, num_saved_registers_ % 2);
// Always an even number of capture registers. This allows us to
// unroll the loop once to add an operation between a load of a register
// and the following use of that register.
for (int i = 0; i < num_saved_registers_; i += 2) {
__ lw(a2, register_location(i));
__ lw(a3, register_location(i + 1));
if (i == 0 && global_with_zero_length_check()) {
// Keep capture start in a4 for the zero-length check later.
__ mov(t7, a2);
}
if (mode_ == UC16) {
__ sra(a2, a2, 1);
__ Addu(a2, a2, a1);
__ sra(a3, a3, 1);
__ Addu(a3, a3, a1);
} else {
__ Addu(a2, a1, Operand(a2));
__ Addu(a3, a1, Operand(a3));
}
__ sw(a2, MemOperand(a0));
__ Addu(a0, a0, kPointerSize);
__ sw(a3, MemOperand(a0));
__ Addu(a0, a0, kPointerSize);
}
}
if (global()) {
// Restart matching if the regular expression is flagged as global.
__ lw(a0, MemOperand(frame_pointer(), kSuccessfulCaptures));
__ lw(a1, MemOperand(frame_pointer(), kNumOutputRegisters));
__ lw(a2, MemOperand(frame_pointer(), kRegisterOutput));
// Increment success counter.
__ Addu(a0, a0, 1);
__ sw(a0, MemOperand(frame_pointer(), kSuccessfulCaptures));
// Capture results have been stored, so the number of remaining global
// output registers is reduced by the number of stored captures.
__ Subu(a1, a1, num_saved_registers_);
// Check whether we have enough room for another set of capture results.
__ mov(v0, a0);
__ Branch(&return_v0, lt, a1, Operand(num_saved_registers_));
__ sw(a1, MemOperand(frame_pointer(), kNumOutputRegisters));
// Advance the location for output.
__ Addu(a2, a2, num_saved_registers_ * kPointerSize);
__ sw(a2, MemOperand(frame_pointer(), kRegisterOutput));
// Prepare a0 to initialize registers with its value in the next run.
__ lw(a0, MemOperand(frame_pointer(), kInputStartMinusOne));
if (global_with_zero_length_check()) {
// Special case for zero-length matches.
// t7: capture start index
// Not a zero-length match, restart.
__ Branch(
&load_char_start_regexp, ne, current_input_offset(), Operand(t7));
// Offset from the end is zero if we already reached the end.
__ Branch(&exit_label_, eq, current_input_offset(),
Operand(zero_reg));
// Advance current position after a zero-length match.
__ Addu(current_input_offset(),
current_input_offset(),
Operand((mode_ == UC16) ? 2 : 1));
}
__ Branch(&load_char_start_regexp);
} else {
__ li(v0, Operand(SUCCESS));
}
}
// Exit and return v0.
__ bind(&exit_label_);
if (global()) {
__ lw(v0, MemOperand(frame_pointer(), kSuccessfulCaptures));
}
__ bind(&return_v0);
// Skip sp past regexp registers and local variables..
__ mov(sp, frame_pointer());
// Restore registers s0..s7 and return (restoring ra to pc).
__ MultiPop(registers_to_retain | ra.bit());
__ Ret();
// Backtrack code (branch target for conditional backtracks).
if (backtrack_label_.is_linked()) {
__ bind(&backtrack_label_);
Backtrack();
}
Label exit_with_exception;
// Preempt-code.
if (check_preempt_label_.is_linked()) {
SafeCallTarget(&check_preempt_label_);
// Put regexp engine registers on stack.
RegList regexp_registers_to_retain = current_input_offset().bit() |
current_character().bit() | backtrack_stackpointer().bit();
__ MultiPush(regexp_registers_to_retain);
CallCheckStackGuardState(a0);
__ MultiPop(regexp_registers_to_retain);
// If returning non-zero, we should end execution with the given
// result as return value.
__ Branch(&return_v0, ne, v0, Operand(zero_reg));
// String might have moved: Reload end of string from frame.
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
SafeReturn();
}
// Backtrack stack overflow code.
if (stack_overflow_label_.is_linked()) {
SafeCallTarget(&stack_overflow_label_);
// Reached if the backtrack-stack limit has been hit.
// Put regexp engine registers on stack first.
RegList regexp_registers = current_input_offset().bit() |
current_character().bit();
__ MultiPush(regexp_registers);
Label grow_failed;
// Call GrowStack(backtrack_stackpointer(), &stack_base)
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments, a0);
__ mov(a0, backtrack_stackpointer());
__ Addu(a1, frame_pointer(), Operand(kStackHighEnd));
__ li(a2, Operand(ExternalReference::isolate_address(masm_->isolate())));
ExternalReference grow_stack =
ExternalReference::re_grow_stack(masm_->isolate());
__ CallCFunction(grow_stack, num_arguments);
// Restore regexp registers.
__ MultiPop(regexp_registers);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ Branch(&exit_with_exception, eq, v0, Operand(zero_reg));
// Otherwise use return value as new stack pointer.
__ mov(backtrack_stackpointer(), v0);
// Restore saved registers and continue.
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
SafeReturn();
}
if (exit_with_exception.is_linked()) {
// If any of the code above needed to exit with an exception.
__ bind(&exit_with_exception);
// Exit with Result EXCEPTION(-1) to signal thrown exception.
__ li(v0, Operand(EXCEPTION));
__ jmp(&return_v0);
}
}
CodeDesc code_desc;
masm_->GetCode(&code_desc);
Handle<Code> code = isolate()->factory()->NewCode(
code_desc, Code::ComputeFlags(Code::REGEXP), masm_->CodeObject());
LOG(masm_->isolate(), RegExpCodeCreateEvent(*code, *source));
return Handle<HeapObject>::cast(code);
}
void RegExpMacroAssemblerMIPS::GoTo(Label* to) {
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
void RegExpMacroAssemblerMIPS::IfRegisterGE(int reg,
int comparand,
Label* if_ge) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_ge, ge, a0, Operand(comparand));
}
void RegExpMacroAssemblerMIPS::IfRegisterLT(int reg,
int comparand,
Label* if_lt) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_lt, lt, a0, Operand(comparand));
}
void RegExpMacroAssemblerMIPS::IfRegisterEqPos(int reg,
Label* if_eq) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_eq, eq, a0, Operand(current_input_offset()));
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerMIPS::Implementation() {
return kMIPSImplementation;
}
void RegExpMacroAssemblerMIPS::LoadCurrentCharacter(int cp_offset,
Label* on_end_of_input,
bool check_bounds,
int characters) {
ASSERT(cp_offset >= -1); // ^ and \b can look behind one character.
ASSERT(cp_offset < (1<<30)); // Be sane! (And ensure negation works).
if (check_bounds) {
CheckPosition(cp_offset + characters - 1, on_end_of_input);
}
LoadCurrentCharacterUnchecked(cp_offset, characters);
}
void RegExpMacroAssemblerMIPS::PopCurrentPosition() {
Pop(current_input_offset());
}
void RegExpMacroAssemblerMIPS::PopRegister(int register_index) {
Pop(a0);
__ sw(a0, register_location(register_index));
}
void RegExpMacroAssemblerMIPS::PushBacktrack(Label* label) {
if (label->is_bound()) {
int target = label->pos();
__ li(a0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
} else {
Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
Label after_constant;
__ Branch(&after_constant);
int offset = masm_->pc_offset();
int cp_offset = offset + Code::kHeaderSize - kHeapObjectTag;
__ emit(0);
masm_->label_at_put(label, offset);
__ bind(&after_constant);
if (is_int16(cp_offset)) {
__ lw(a0, MemOperand(code_pointer(), cp_offset));
} else {
__ Addu(a0, code_pointer(), cp_offset);
__ lw(a0, MemOperand(a0, 0));
}
}
Push(a0);
CheckStackLimit();
}
void RegExpMacroAssemblerMIPS::PushCurrentPosition() {
Push(current_input_offset());
}
void RegExpMacroAssemblerMIPS::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
__ lw(a0, register_location(register_index));
Push(a0);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerMIPS::ReadCurrentPositionFromRegister(int reg) {
__ lw(current_input_offset(), register_location(reg));
}
void RegExpMacroAssemblerMIPS::ReadStackPointerFromRegister(int reg) {
__ lw(backtrack_stackpointer(), register_location(reg));
__ lw(a0, MemOperand(frame_pointer(), kStackHighEnd));
__ Addu(backtrack_stackpointer(), backtrack_stackpointer(), Operand(a0));
}
void RegExpMacroAssemblerMIPS::SetCurrentPositionFromEnd(int by) {
Label after_position;
__ Branch(&after_position,
ge,
current_input_offset(),
Operand(-by * char_size()));
__ li(current_input_offset(), -by * char_size());
// On RegExp code entry (where this operation is used), the character before
// the current position is expected to be already loaded.
// We have advanced the position, so it's safe to read backwards.
LoadCurrentCharacterUnchecked(-1, 1);
__ bind(&after_position);
}
void RegExpMacroAssemblerMIPS::SetRegister(int register_index, int to) {
ASSERT(register_index >= num_saved_registers_); // Reserved for positions!
__ li(a0, Operand(to));
__ sw(a0, register_location(register_index));
}